Unity3d - Need to hide a group of objects in the area - unity3d

Question

I've already tried depthmask shaders and examined some other ideas, but it seems like it doesn't suit me at all.
I'm making an AR game and I have a scene with a house and trees. All these objects are animated and do something like falling from the sky, but not all at once, but in sequence. For example, the house first, then trees, then fence etc.
(Plz, look at my picture for details) http://f2.s.qip.ru/bVqSAgcy.png
If user moves camera too far, he will see all these objects stucking in the air and waiting for their order to start falling, and it is not good. I want to hide this area from all sides (because in AR camera can move around freely) and make all parts visible only when each will start moving (falling down).
(One more screen) http://f3.s.qip.ru/bVqSAgcz.png
I thought about animation events, but there are too many objects (bricks, for example) and I can't handle all of them manually.
I look forward to your great advice ;)
P.S. Sorry for my bad english.

Answer 1

You can disable their(the objects that are gonna fall) mesh renderers and re active them when they are ready to fall.
See here for more details about mesh renderer.

Answer 2

Deactivate your Object. You might use the camera viewport coordinates to get a y position outside the viewport. They start on the bottom left of the screen (0,0) and go to the top right of the screen (1,1). Convert them to worldspace coordinates. Camera.ViewportToWorldPoint
Vector3 outsideCamera = Camera.main.ViewportToWorldPoint(new Vector3(0.5f, 1.2f, 10.0f));
Now you can use the intended x and z positions of your object. Activate it when you want to drop it.
myObject.transform.position = new Vector3(myObject.transform.position.x, outsideCamera.y, myObject.transform.position.z);
Another thing you could additionally do is scaling the object from very small to its intended size when it is falling. This would prevent the object being visible before falling when the users point the camera upwards.

Answer 3

1- Maybe you can use the Camera far clipping plane property.
Or you can even use 2 Cameras if you need to display let's say the landscape on one (which will not render the house + trees + ...) with a "big" far clipping plane and use a second one with Depth only clear flags rendering only the items (this one can have a smaller far clipping plane from what I understand).
2- Other suggestion I'd give you is adding the scale to your animation:
set the scale to 0 on the beginning of animation
wait for the item to be needed to fall down
set the scale to 1 (with a transition if needed)
make the item fall down
EDIT: the workaround you found is quite just fine too! But tracking only world position should be enough I think (saving a tiny amount of memory).
Hope this helps,

Answer 4

Finally, the solution I chose. I've added this script to each object in composition. It stores object's position (in my case both world and local) at Start() and listening if it changes in Update(). So, if true, stop monitoring and set MeshRenderer in on state.
[RequireComponent(typeof(MeshRenderer))]
public class RenderScript : MonoBehaviour
{
private MeshRenderer mr;
private bool monitoring = true;
private Vector3 posLocal;
private Vector3 posWorld;
// Use this for initialization
void Start()
{
mr = GetComponent<MeshRenderer>();
mr.enabled = false;
posLocal = transform.localPosition;
posWorld = transform.position;
}
// Update is called once per frame
void Update()
{
if (monitoring)
{
if (transform.localPosition != posLocal || transform.position != posWorld)
{
monitoring = false;
mr.enabled = true;
}
}
}
}
Even my funny cheap сhinese smartphone is alive after this, so, I guess, it's OK.